Urine is sterile until it makes contact with the genitalia. Then it becomes contaminated. Depending on where your genitals have been and what has been in contact with them. Well, I wouldn't count on drinking sterile urine straight from the source. Now, if you insert a urinary catheter to drain directly from the bladder, then you will have sterile urine. However, you must clean the genital area with iodine first and must use aseptic technique when inserting said catheter. In other words, it is not a one-person job unless one had lots of practice.
As far as urine containing chemicals your body needs - if your body needed them, they would not be excreted unless you have a major illness or are on some med that prohibits absorption. Urine contains many waste products that the body cannot use and can be toxic if not excreted - products such as urea, ammonia, uric acid and creatinine. The largest urine content (besides water is urea (which is derived from the breakdown of proteins and amino acids in the diet and in the body itself).
So you drank some piss! I don't think it will kill you (had an alcoholic patient who drank 700 cc of the stuff in two or three gulps because he thought it was beer and it did not kill him). As long as your body can get rid of these chemicals, you're OK. If it can't, then you have some problems that you really don't want.
Offered by Lyn.